Question to the HM Treasury:

To ask Mr Chancellor of the Exchequer, what effect reducing the top rate of tax from 50 per cent to 45 per cent has had on total tax receipts since 2012.

HMRC does not routinely evaluate the effects of specific policies on tax receipts. The estimated cost of reducing the additional rate of income tax to 45 per cent is available on the government website, Budget 2013, page 66, table 2.2:

https://www.gov.uk/government/publications/budget-2013-documents

HMRC published a detailed evaluation of the impact of the 50 per cent tax rate on the Exchequer in 2012 ‘The Exchequer effect of the 50 per cent additional rate of income tax’. This report contains more information on the methodology for estimating the impact of the policy, specifically in annex A:

http://webarchive.nationalarchives.gov.uk/20130127161217/http://www.hmrc.gov.uk/budget2012/excheq-income-tax-2042.pdf